1. Field
Methods and apparatuses consistent with the exemplary embodiments relate to a magnetic resonance imaging (MRI) apparatus and method, and more particularly, to an MRI apparatus and method which are capable of processing a plurality of K-space data in parallel by using a radio frequency multiple coil.
2. Description of the Related Art
An MRI apparatus uses a magnetic field to obtain an image of a subject, and is widely used in order to accurately diagnose diseases because it is capable of showing stereoscopic images of bones, disks, joints, and nerve ligaments at desired angles.
The MRI apparatus is configured to acquire a magnetic resonance (MR) signal and reconstruct the MR signal into an image for output. Specifically, the MRI apparatus acquires an MR signal by using radio frequency (RF) coils, a permanent magnet, and gradient coils. During reconstruction of K-space data, acquired by the RF coils, into an MR image, noise present in the K-space data may be amplified.
In order to output an MR image in which such amplified noise has been removed, the acquired MR signal has to be corrected by performing image processing, such as calibration.
A Generalized Auto-calibrating Partially Parallel Acquisition (GRAPPA) technique based on a K-space is an MRI method for processing an acquired MR signal.
The GRAPPA technique that is a K-space-based imaging method includes computing spatial correlation coefficients or convolution kernel coefficients that are spatial interaction values between a calibration signal and an adjacent measured source signal by performing self-calibration and estimating unmeasured signals by using the calculated spatial correlation coefficients.
In detail, the GRAPPA technique restores missing K-space lines for each channel by using measured signals that are undersampled data and additional auto-calibrating (ACS) lines.
When data of an image signal is damaged due to noise, or spatial interaction values vary, aliasing artifacts and noise amplification may occur in a finally acquired MR image.
Thus, there is a need for an imaging apparatus and method which are capable of reconstructing an MR image having an improved quality by reducing aliasing artifacts and suppressing amplified noise.